A new high-power-factor three-phase AC-DC converter: Analysis, design, andexperimentation

This paper proposes a new high-power-factor three-phase ac-de converter, wh ich is composed of a line interphase transformer (LIT) and two three-phase diode rectifiers, followed by a pulsewidth modulation (PWM) dc-dc boost con verter. The active switch of the boost converter is gated at a constant frequency s uch that the ac input current is discontinuous. This procedure provides an input current shaping without the third, fifth, and seventh harmonics. The currents that flow through the LIT and boost inductors have such a high-swi tching frequency that ferrite cores with a small size can be utilized. In addition, the output voltage is regulated by PWM to compensate for line voltage variations and load change. Theoretical analysis, design procedure and example, along with experimental results taken from a 6-kW laboratory prototype are given.